Launch from Cape Canaveral (KSC); landing on Cape Canaveral (KSC). The fourth Space Station assembly flight ISS-2A.2b utilized the SPACEHAB Double Module and the Integrated Cargo Carrier (ICC) to bring supplies to the station.

The goal of the flight was to prepare Zvezda for the arrival of the first residents, or Expedition, crew later in the fall of 2000 and the start of a permanent human presence on the new outpost.

Following a two day solo flight the Atlantis docked with the ISS on September 10, 2000.

The only EVA was performed by Edward Lu and Yuri Malenchenko on September 11, 2000 (6h 15m) to complete final connections (electrical-, data- and television cables) between Zvezda module and component Zarya. A magnometer was boomed to a port of Zvezda module. The magnetometer serves as a three-dimensional compass designed to minimize Zvezda propellant usage by relaying information to the module's computers regarding its orientation relative to the Earth.

On flight day four the crew entered the International Space Station through Pressurized Mating Adapter-2 (PMA-2) to begin the transfer operations of more than three tons of hardware and supplies. Transfer of supplies and maintenance tasks continued well into the fifth day, while orbiter consumables remained above the required levels allowing managers to extend the mission one additional day. Finally they placed two Russian Orlan space suits near the air lock.